Actually, a good spring/coilover mix can actually outperform even the best coilovers depending on what you mix up in the equation. I remember a thread on a different forum that was talking about all the virtues of the "better" coilovers. The result was basically favorable for coilovers, but not all agreed:
1) Cheap coilovers were not even part of the discussion. Cheap, meaning $1K and under coilovers, though for whatever reason, $1500 ones strike a magic figure because some in the $1500 range, while inferior to the better quality $3-$5K ones, are still very very good). So cheap should not be considered at all, period, unless the brand has been tested and is well reviewed in spite the cheap price tag.
2) Majority agreed a more expensive coilover setup was superior to the strut/spring setup because they are rebuildable for not too much, can adjust in mega/seemingly countless ways, and can be made for a soft or a harsh ride...simply the most versatile setup, really.
3) This said, a few chimed in stating they would never give away their strut/spring/tophat combo especially when people riding in their car and going on "handling" based runs or being used to auto-x in them have found them to be superior to their coilovers.
In the end, I would go with either the very best bang for buck strut/spring/tophat combo out there that competes with the better coilovers especially if "major" adjustability is not required.